Think of the Quickbuild feature as the “Autopilot” of the filter. Clicking this button will automatically create all available sizes and bit depths for an icon.
If you want to create only a certain kind of resources (say just the 256 color versions for instance), select any cell in the 256 (or 8-bit) column and click Control-QuickBuild.
If you want to only auto-create a particular sized icon (say the 32×32 or large icons) then select any cell in that column and click Shift-QuickBuild. Remember: Control-clicking only affects columns, and Shift-clicking only affects rows.
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